Grim Adventures Of Billy & Mandy - Nintendo Wii Whether players use Billy's berserk attack or Mandy's deadly smile, all characters feature unique abilities based on their personality Mission Mode can be played as either a single-player or a two person cooperative game -- takes players through 45 missions with unlockable rewards & new characters In battle mode, up to four players can choose characters, arenas, weapons and battle parameters to unleash a fierce competition to be the Last One Standing Features the unpredictable environments that Billy, Mandy, Grim and Irwin visit in the show -- from Billy's house to the Afterlife to Toadblatt's Coliseum Players can smash objects, destroy environments and battle in eight fully interactive arenas